A trend for multifunctional electronic devices including a cellular phone having lightweight, thin, short, and small electronic devices has never stopped. Further, there has been a demand for a technology of inserting electronic components, such as an integrated circuit (I/C), a semiconductor chip, or an active device, and a passive device, into a circuit board. Recently, a technology of embedding a component in the circuit board in various ways has been developed.
A general component embedded circuit board has a cavity in an insulating layer of the board and inserts electronic components such as an IC and a semiconductor chip in the cavity. Thereafter, adhesive resin such as a prepreg is coated on an inner portion of the cavity, and the insulating layer into which the electronic components are inserted. Then, the electronic components are fixed by coating the adhesive resin, and the insulating layer is formed.